🔍 CF StatLens

Elevate your Codeforces profile with granular daily analytics, accuracy tracking, and difficulty breakdowns directly inside your heatmap.

CF StatLens is a lightweight, blazing-fast browser extension that replaces the default Codeforces heatmap tooltips with deep, actionable insights. Designed for competitive programmers who want to track their real productivity, not just their submission count.

✨ Features

• 🔥 Contextual Streak Tracking: Instantly see your active streak relative to the day you are hovering over.
• 🎯 Accuracy Metrics: Calculates your daily Accepted/Total ratio with color-coded progress bars.
• 📊 Difficulty Breakdown: Groups your accepted problems by exact rating (e.g., 800, 1400, 1900) so you know exactly what level you practiced.
• 🏷️ Top Topics: Dynamically aggregates the tags of your accepted problems to show your primary focus for the day.
• 🏆 Global Targets: Always displays your "Most Productive Day" (highest AC) and "Highest Grind Day" (most submissions) as benchmarks to beat.
• ⚡ Zero-Lag Caching: Uses localStorage to cache API responses, meaning the tooltip loads instantly without rate-limiting the Codeforces servers.

📸 Screenshots

 

🛠️ Installation (Developer Mode)

Want to try it locally or contribute? You can install the extension directly from this source code.

1. Clone this repository:

   git clone https://github.com/YOUR_USERNAME/CF-StatLens.git

2. Open your Chromium-based browser (Chrome, Edge, Brave).
3. Navigate to the extensions page: chrome://extensions/
4. Enable "Developer mode" (toggle in the top right corner).
5. Click "Load unpacked" and select the folder where you cloned this repository.
6. Open any Codeforces profile and hover over the heatmap!

⚙️ How it Works under the Hood

Instead of spamming the Codeforces server with an API call every time you hover over a cell, CF StatLens is highly optimized:

1. Initial Fetch: Makes a single request to the user.status endpoint on initial page load.
2. Data Structuring: Processes thousands of raw submissions into a O(1) lookup Hash Map stored in RAM.
3. Local Storage: Caches the structured map in the browser's hard drive for 10 minutes to survive page reloads and protect network bandwidth.
4. DOM Manipulation: Aggressively suppresses native tooltips (tippy-box, cal-heatmap-tooltip) to inject a custom-styled floating element on hover.

💻 Tech Stack

• Vanilla JavaScript (ES6+)
• CSS3 (Catppuccin Dark Mode Theme)
• HTML5
• WebExtensions API (Manifest V3)
• Official Codeforces API

🤝 Contribution

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

📝 License

MIT